Electric Bikes - Yamaha PAS help

Hi all,

I got this bike from a used bike yard.

Yamaha PAS Superlight (Intelligent battery)

Its has a 2 speed hub with hub motor (don't know the wattage).
I think the motor is brushed, since I can run the motor with DC (without any circuit).
No charger.
good condition NiCd battery.

I used a external charger to charge the battery without the intelligent system. It works fine. But I think, since I'm not using the intelligent charging system, My NiCd will go wasted pretty soon. In which case, I'm thinking of replacing the battery pack with two 12v motor cycle gel batteries. What do U guy's think about this?

I was also wondering why they haven't built regenerative brakes into these bikes. I realize that the motor is freewheeled and there is no external way to engage the motor to the wheel on braking.

Anyone has experienced with these bike, can I modify (or is it already there?) the hub to have re-generative brakes.

Please help me on this.

Thanks,
Harshana

For bikes, setting up the to allow regenerative braking instead of freewheeling would mean it's harder to pedal without motor power. Depending on the circumstances, it could either decrease or increase the range you get-- the increase in drag if you spin the motor without needing it either for power or for braking isn't so good.

It'd also require better ( = more expensive) electronics.

I thought regenerative brakes will only engage the motor when U squeeze the brake lever... Isn't that the case ?.

I'm not too much worried about electronics as, I'm happy DIY cct builder with uControllers.

What do U guys think of replacing the NiCd with motor cycle batteries?

Thanks,
Harshana

I thought regenerative brakes will only engage the motor when U squeeze the brake lever... Isn't that the case ?.

I'm not too much worried about electronics as, I'm happy DIY cct builder with uControllers.

What do U guys think of replacing the NiCd with motor cycle batteries?

Thanks,
Harshana

Well, SLA/AGM batteries are a common choice. They'll be heavier than your NiCad will, and you'll need to make sure you charge them soon after use, but they're low cost. EDIT: Mm, not just motorcycle batteries. Same chemistry, but different use. You need deep discharge.

NiMH and Lithium cost considerably more, but also last considerably longer and are much lighter.

Any of them will work fine, it just depends on what you value.
NiCad is a horrible environmental liability if not disposed of properly, keep that in mind too when you need to replace it.

You're correct in thinking that a bad charger will kill your NiCad pack unduly fast, it's gonna bake & dry out. I'm thinking the charger matters as much as the cells used in these things. Anyways ebikes.ca has some decent ones. But you may want to do a load test first, check the cells to see if the battery is starting to go south.

If you meant motorcycle starting batteries, they're made for dishing out amps during short bursts and really don't like getting discharged. For a power-assist bicycle you'd need something like UPS batteries in order to get decent life out of them.
http://www.gruberpower.com/gruberpower/advertising/Batteries/scooterbatteries/


Pictures of the bike and it's works would be welcome.